Von der empirischen zur abstrakten Kryptographie

Cryptography has been employed for more than three thousand of years to get privacy in communications. But purpose and application of cryptography grew with nearly exponentially speed of development. Now it is an important tool for overall security in information technology. The aim of this paper is to show this development which started empirically and lead to the “abstract cryptography” of today. To make transparent what cryptography is and how it has been grown to its present state abstraction helps to find out the single steps of development. In the first section a brief overview shows what is meant under the term “abstraction”. The second section contains explanations of the specific terms used. The following sections show the steps which lead to the first two of totally three possible levels of abstraction. A look at the state of the art and future directions closes the article.     

Automatisierte Generierung und Auswertung von Finite-Elemente-Modellen elektrischer Großmaschinen zur Ermittlung von Kennwerten

The producers of electric machinery are nowadays confronted with the quite formidable task to offer their products on a heavily competitive international market, with steadily decreasing delivery-time and increasing demands on the quality and performance of the electric machines. Therefore, to maintain competiveness, it is necessary, besides innovative processes in design, manufacturing and support during the working cycle, to employ sophisticated computation methods in order to make better estimates of the loading of the active parts and to recognize their limitations more accurately and at an earlier stage. For this purpose, besides computer-based analytical methods, numerical calculations are applied. In this report, the use of a standard-finite element program in a specific computation package (consisting of data conversion, geometry processing, result evaluation and command structures which intend to liberate the user as much as possible from the direct interaction with the FE programs) for the calculation of electromagnetic field in large electric machines and their derived quantities, e. g. excitation currents and reactances, at Elin Energieversorgung GmbH is described.     

Harnessing the Power of GPUs to Speed Up Feature Selection for Outlier Detection

Acquiring a set of features that emphasize the differences between normal data points and outliers can drastically facilitate the task of identifying outliers. In our work, we present a novel non-parametric evaluation criterion for filter-based feature selection which has an eye towards the final goal of outlier detection. The proposed method seeks the subset of features that represent the inherent characteristics of the normal dataset while forcing outliers to stand out, making them more easily distinguished by outlier detection algorithms. Experimental results on real datasets show the advantage of our feature selection algorithm compared with popular and state-of-the-art methods. We also show that the proposed algorithm is able to overcome the small sample space problem and perform well on highly imbalanced datasets. Furthermore, due to the highly parallelizable nature of the feature selection, we implement the algorithm on a graphics processing unit （GPU） to gain significant speedup over the serial version. The benefits of the GPU implementation are two-fold, as its performance scales very well in terms of the number of features, as well as the number of data points.     

OpenMC： Towards Simplifying Programming for TianHe Supercomputers

Modern petascale and future exascale systems are massively heterogeneous architectures. Developing productive intra-node programming models is crucial toward addressing their programming challenge. We introduce a directive- based intra-node programming model, OpenMC, and show that this new model can achieve ease of programming, high performance, and the degree of portability desired for heterogeneous nodes, especially those in TianHe supercomputers. While existing models are geared towards oifloading computations to accelerators （typically one）, OpenMC alms to more uniformly and adequately exploit the potential offered by multiple CPUs and accelerators in a compute node. OpenMC achieves this by providing a unified abstraction of hardware resources as workers and facilitating the exploitation of asynchronous task parallelism on the workers. We present an overview of OpenMC, a prototyping implementation, and results from some initial comparisons with OpenMP and hand-written code in developing six applications on two types of nodes from TianHe supercomputers.     

Data modeling and method analysis for brain imaging genetics

Brain imaging genetics is a popular research topic on evaluating the association between genetic variations and neuroimaging quantitative traits (QTs). As a bi‐multivariate analysis method, sparse canonical correlation analysis (CCA) is a useful technique which identifies efficiently genetic diseases on the brain with modeling dependencies between the variables of genotype data and phenotype data. The initial efforts on evaluating several space CCA methods are made for brain imaging genetics. A linear model is proposed to generate realistic imaging genomic data with selected genotype‐phenotype associations from real data and effectively capture the sparsity underlying projects. Three space CCA algorithms are applied to the synthetic data, and show better or comparable performance on the synthetic data in terms of the estimated canonical correlations. They have successfully identified an important association between genotype and phenotype. Experiments on simulated and real imaging genetic data show that approximating covariance structure using an identity or diagonal matrix and the approach used in these space CCA algorithms could limit the space CCA capability in identifying the underlying imaging genetics associations. Further development depends largely on enhanced space CCA methods that effectively pay attention to the covariance structures in simulated and real imaging genetics data.     

Cost-effective multi-pulse AC-DC converter with lower than 3% current THD

In this paper, a new multi-pulse clean power converter topology is presented with lower than 3% input current total harmonic distortion (THD). The topology is based on the combination of a 36-pulse converter and a pulse doubling circuit. The 36-pulse converter consists of a “polygon” autotransformer and two 18-pulse diode bridge rectifiers. Pulse doubling circuit consists of zero-sequence-blocking transformer (ZSBT) and tapped interphase transformer (IPT). The important advantage of the proposed AC-DC converter is considerable reduction in burdens of the magnetic parts with respect to the nominal load rating. It provides more economical solution to achieve harmonic mitigation in electric power systems as compared with other 72-pulse AC-DC converters. The simulation and experimental results show that the input current THD is less than 3% using the proposed topology. The results indicate a significant reduction in the total cost and volume of the proposed 72-pulse configuration in comparison with similar configurations. Also, it is shown that the proposed converter rating is about 44% of the DC load power.     

HAG：An Energy-Proportional Data Storage Scheme for Disk Array Systems

Energy consumption has been a critical issue for data storage systems, especially for modern data centers. A recent survey has showed that power costs amount to about 50%of the total cost of ownership ...     

Simulation im Bereich der Produktionsplanung und -steuerung (PPS)

Up to now, within the area of PPC, simulation is mainly used for local applications, i. e., particular machines, production lines etc. Missing proceeding models as well as automated interfaces prevented especially small and medium sized producers from comprehensive applications to the whole production process. The paper shows ways to overcome these restrictions and outlines a concrete approach to the coupling of a PPC-System with a simulation tool.     

Bündelung von Telekom-Diensten durch einen E-Commerce-Ansatz

In light of the rapid progress information technology (IT) has been making in both the fixed and wireless network, economic agents have started to focus on electronic commerce in hopes of reaping substantial profits. Faced with stiff, technology-driven competition, enterprises will have to go beyond traditional sales and marketing channels to stay in business. Telecom-providers, in particular, will have to offer cutting-edge technology to their customers. At the same time, organizations will have to implement internal and external structural changes, to attain a comparative advantage from harnessing the latest IT. Intermediation, or the services offered by intermediaries, should allow for transparency, risk minimization and customer-orientation.